Zack Wheeler day was a bust.

The other phenom in the Mets’ rotation didn’t remind anyone of Matt Harvey, but the bullpen bailed him out in a 5-4 win over the Phillies at Citi Field on Saturday.

Wheeler needed one more out to be in line for the win, but couldn’t get it. With a two-run lead, he left with the bases loaded and two out in the fifth, when Terry Collins came out to rescue the young righthander who had thrown 106 pitches in the 93-degree heat.

With none of Wheeler’s hype, another rookie, Gonzalez Germen (1-1), entered to strike out Delmon Young to keep the Mets ahead to stay.

Bobby Parnell would later survive a shaky ninth as the Mets rebounded from their humbling start to the second half — a 13-8 loss on Friday.

“There’s been a few times now I’ve had to come out early because I’m throwing 20 pitches an inning,” Wheeler said. “Falling behind guys like that is not going to work. That’s part of my game. I’ll have to fix it pretty fast.

“Obviously, I want to do good (at Citi Field), but anywhere you are if you’re throwing 20 pitches an inning you’re not going to get very far in the game. That is frustrating as a pitcher.”

It would have been far more frustrating had the Mets lost.

A costly error by Josh Satin and a two-run bomb from Chase Utley off Parnell threatened to derail what was a nearly flawless effort by the Mets’ much-improved bullpen. Domonic Brown followed with a double to put the tying run in scoring position, but Parnell got Darin Ruf to line out to second to earn his 18th save.